How Cryptococcus interacts with the blood-brain barrier.

Cryptococcus demonstrates predilection for invasion of the brain, but the mechanism by which Cryptococcus crosses the blood-brain barrier (BBB) to cause brain invasion is largely unknown. In order for Cryptococcus to cross the BBB, there must be a way to either cross human brain microvascular endothelial cells, which are the main constitute of the BBB, or go in between tight junctions. Recent evidence of human brain microvascular endothelial cell responses to transcellular brain invasions includes membrane rearrangements, intracellular signaling pathways and cytoskeletal activations. Several Cryptococcal genes related to the traversal of BBB have been identified, including CPS1, ITR1a, ITR3c, PLB1, MPR1, FNX1 and RUB1. In addition, Cryptococcus neoformans-derived microvesicles may contribute to cryptococcal brain invasion. Paracellularly, Cryptococcus may traverse across BBB using either routes utilizing plasmin, ammonia or macrophages in a Trojan horse mechanism.

Comparison of the clinical manifestations of infective endocarditis between elderly and young patients - a 3-year study.

BACKGROUND AND PURPOSE: Infective endocarditis (IE) is associated with high morbidity and mortality. This study investigated the clinical manifestations and outcomes of IE and compared them between old and young patients. METHODS: In this retrospective study, data for patients with IE who were treated from November 1, 2003 to October 30, 2006 were collected. Patients were identified as having IE if they met the modified Duke criteria for definitive IE. RESULTS: Seventy two patients were included. The most common symptoms were fever (81%) and dyspnea (50%). Fifty four patients (75%) had culture-positive IE. Staphylococcus aureus (35%) was the most common organism isolated, followed by Streptococcus spp. (26%). Vegetations were detected in 60 patients (83%): mitral valve (MV; 40%), aortic valve (AV; 24%), tricuspid valve (TV; 14%), MV and AV (4%), and pulmonary valve (1%). Thirty nine patients (54%) had embolic complications - 26 older patients (79%) and 13 younger patients (33%). Twenty two patients (31%) died in hospital. There were significant differences in clinical features between older and younger patients. Diabetes mellitus (p